J.M Zeng
,
H. Gu and YH. Zhou (Institute of Materials Science
,
Guangxi University
,
Nanning 530004
,
China Department of Materials Science and Engineering
,
Shanghai Jiaotong University
,
Shanghai 200030
,
China)
金属学报(英文版)
In this paper, the mathematical models for mould-filling under counteramvity are derived on the basis of the principle of momentum. Dynamic processes of mould-filling are observed on a perspex model by means of high speed photography. The results indicate that the mould-filling under counterpmvity can be described by the second oofer nonlinear dtherential equations charucterized by damping oscillations. The velocity oscillations amplofy as the pressuring speed increases if the pressure differential functions are of the same type. On the other hand, if the functions are of different type,then the velocity oscillations depend upon whether the functions pmpressively increase or decrease. Velocity oscillations can be diminished dmmatically by increasing the local damping within the gating system.
关键词:
casting
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